Methods of providing a fragrance to a composition and methods of enhancing fragrances using (di)methyl-substituted cycloot(adi)ene hydroformylation products

ABSTRACT

The use of monocyclic aldehydes as odorous materials, which can be produced through partial or total hydroformylation of (di)methyl-substituted cyclooct(adi)enes, is described. The fragrance enhancing capacity of the compounds is described in methods for their use both as perfumes and perfume enhancers or boosters.

BACKGROUND OF THE INVENTION

The hydroformylation of cyclic dienes is known from the literature. For example, A. Spencer describes the hydroformylation of inter alia 1,3- and 1,5-cyclooctadiene in the presence of special rhodium catalysts in Journal of Organometallic Chemistry 1997, 124, pages 85 to 91. JP 58/21638 describes a process for the production of dialdehydes in which unconjugated diolefins are reacted with hydrogen and carbon monoxide in a water-immiscible solvent in the presence of a rhodium catalyst.

Cyclooctane aldehyde (1)

is disclosed in U.S. Pat. No. 3,985,769 as a raw material for the production of acetal derivatives with perfume properties, its olfactory properties being described as “intensively green”.

Judging by demand, many natural perfumes are available in totally inadequate quantities. Accordingly, it is clear that there is a constant demand in the perfume industry for new perfumes with interesting perfume notes in order to extend the range of naturally available perfumes and to be able to make the necessary adaptations to changing fashion trends and to satisfy the continuously increasing demand for odor enhancers for products of everyday use, such as cosmetics and cleaning products.

In addition, there is generally a constant need for synthetic perfumes which can be favorably produced in a consistent quality and which have desirable olfactory properties, i.e. Pleasant, near-natural and qualitatively new odor profiles of adequate intensity, and which are capable of advantageously influencing the fragrance of cosmetic and consumer products. In other words, there is a constant need for compounds which have characteristic new odor profiles coupled with high staying power, intensity of odor and emanative power.

BRIEF SUMMARY OF THE INVENTION

The present invention includes methods of using monocyclic aldehydes obtainable by partial or complete hydroformylation of a (di)methyl-substituted cyclooct(adi)ene, for providing fragrances to compositions and/or enhancing already existing fragrances. As used herein, “cyclooct(adi)ene” includes both cyclooctadienes and/or cyclooctenes. Also, as used herein, “(di)methyl-substituted” refers to one or more methyl group substituents located on cyclic ring of the cyclooct(adi)ene species.

It has surprisingly been found that aldehydes obtainable by partial or complete hydroformylation of (di)methyl-substituted cyclooct(adi)enes have remarkable olfactory properties. Over and above their special odor characteristic, which is characterized by a broad range with complex nuances, the compounds are distinguished by high staying and emanative power. In addition, they are eminently suitable as perfume boosters. A perfume booster is understood to be a substance which is capable of lastingly intensifying the olfactory impressions of the components of a multicomponent system, i.e. a mixture of two or more perfumes.

The present invention relates to the use of monocyclic aldehydes obtainable by partial or complete hydroformylation of (di)methyl-substituted cyclooct(adi)enes as perfumes.

The present invention also relates to the use of monocyclic aldehydes obtainable by partial or complete hydroformylation of (di)methyl-substituted cyclooct(adi)enes as perfume boosters. Compounds (3a), (3b) and (3c) described in more detail hereinafter are particularly preferred for

DETAILED DESCRIPTION OF THE INVENTION

The aldehydes to be used in accordance with the invention are advantageously prepared by hydroformylation of (di)methyl-substituted cyclooct(adi)enes which have a cyclooctane system as a common backbone. The backbone is illustrated by formula (2) below, but without any methyl groups or C═C double bonds:

The system (2) contains one or two methyl groups and one or two C═C double bonds. If two C═C double bonds are present, they are not immediately adjacent.

The hydroformylation is a reaction known to the expert which was discovered by Roelen in 1938. In this reaction, alkenes are converted into aldehydes with carbon monoxide and hydrogen. The reaction is also known as oxosynthesis.

If (di)methyl-substituted cyclooctadienes are used as starting materials for the purposes of the present invention, the hydroformylation may be carried out in part or completely. In the case of partial hydroformylation, one olefinic double bond remains intact per molecule of the starting compound while only the other is hydroformylated; in the case of complete hydroformylation, two CHO groups are introduced into the molecule. If, however, (di)methyl-substituted cyclooctenes are used as starting materials, only complete hydroformylation is of course possible because only one olefinic double bond is present per molecule of the starting compound.

The odor profile of the hydroformylation products according to the invention is original and novel. In perfume compositions, they enhance harmony and emanation and also staying power, the particular dosage being adapted to the perfume note required taking the other constituents of the composition into account.

The fact that the hydroformylation products according to the invention have interesting perfume notes was not foreseeable and is confirmation of the general experience that the olfactory properties of known perfumes are not necessarily an indication of the properties of structurally related compounds—in the present case cyclooctane aldehyde (1) for example—or mixtures thereof because neither the mechanism of odor perception nor the influence of chemical structure on odor perception has been sufficiently researched, i.e. it cannot normally be predicted whether a modified structure or special mixing ratios of known perfumes lead at all to changes in the olfactory properties and whether these changes may be regarded as positive or negative.

By virtue of their odor profiles, the hydroformylation products according to the invention are also particularly suitable for modifying and enhancing known compositions. Particular emphasis is placed above all on their outstanding intensity of odor which contributes quite generally towards the refinement of compositions.

Also remarkable is the way in which the hydroformylation products according to the invention round off and harmonize the perfume notes of a broad range of known compositions without unpleasantly dominating them in any way.

Compounds (3a), (3b) and (3c)—cf, the structural formulae shown below—are most particularly suitable for use as a perfume and/or perfume booster in accordance with the invention. Accordingly, it is of particular advantage to use the compounds (3a), (3b) and (3c) in air fresheners for example. In addition, it has been found that the compounds (3a), (3b) and (3c) may be used with particular advantage for enhancing citrus notes in cleaning compositions.

Compounds (3a), (3b) and (3c) may be prepared, for example, by hydroformylation of the corresponding (di)methyl-substituted cyclooctene or cyclooctadiene systems.

Compound (3b) is generally obtained in the form of an (E,Z)-mixture, in other words the C═C double bond may be both E- and Z-configured, although a mixture in which the Z configuration predominates is generally present. However, it may even be desirable to use the E- or Z-configured form in pure substance.

The quantities in which the hydroformylation products according to the invention are used in perfume compositions are between 0.001 and 70% by weight, based on the mixture as a whole. The hydroformylation products according to the invention and corresponding compositions may be used both for perfuming cosmetic preparations, such as lotions, creams, shampoos, soaps, salves, powders, aerosols, toothpastes, mouthwashes, deodorants, and in extract perfumery. They may also be used for perfuming technical products and detergents and cleaning compositions, fabric softeners, textile treatment compositions and tobacco. For perfuming these various products, the compositions are added to them in an olfactorily effective quantity, more particularly in a concentration of 0.05 to 2% by weight, based on the product as a whole. However, these values are not intended to represent limits because the experienced perfumist can still obtain effects with lower concentrations or can build up new complexes with even higher concentrations.

The following Examples are intended to illustrate the invention without limiting it in any way.

EXAMPLES 1. Preparation of 2,6-dimethyl-1-formylcyclooctane (3a)

2 Moles (272.46 g) of 1,5-dimethyl-1,5-cyclooctadiene (manufacturer: Shell; gas chromatographic purity: 75%) were introduced into an autoclave together with 1.7 mmoles (1.175 g) of a rhodium catalyst with the formula Rh(CO)CI(PPh₃)₂ and 19 mmoles (5 g) of triphenyl phosphine and reacted with a 1:1 mixture of hydrogen and carbon monoxide with intensive stirring for 5 hours at 100° C. under a pressure of 60 kg/cm² and in the absence of solvent. For working up, the contents of the reactor were filtered and distilled through a 20 cm Vigreux column.

Subsequent fractionation was carried out in a spinning band column. 82 g of monoaldehyde (3a) (boiling point: 65° C./16 mbar) were obtained together with 35.4 g of dialdehyde (boiling point: 105° C./16 mbar).

Odor description for (3a): minty, woody, cucumber-dill note.

2. Preparation of 2,6dimethyl-5-formylcyclooct-1-ene (3b)

2 Moles (272.46 g) of 1,5-dimethyl-1,5-cyclooctadiene (manufacturer: Aldrich; gas chromatographic purity: 76%) were introduced into an autoclave together with 1.7 mmoles (1.175 g) of a rhodium catalyst with the formula Rh(CO)Cl(PPh₃)₂ and 19 mmoles (5 g) of triphenyl phosphine and reacted with a 1:1 mixture of hydrogen and carbon monoxide with intensive stirring for 5 hours at 100° C. under a pressure of 60 kg/cm² and in the absence of solvent. For working up, the contents of the reactor were filtered and distilled through a 20 cm Vigreux column.

Subsequent fractionation into educt and monoaldehyde was carried out in a spinning band column. 132 g of product (3b) were obtained (boiling point: 58° C./16 mbar).

Odor description: technical

3. Preparation of 2,6-dimethyl-1,5-diformylcyclooctane (3c)

2 Moles (272.46 g) of 1,5-dimethyl-1,5-cyclooctadiene manufacturer: Shell; gas chromatographic purity: 98%) were introduced into an autoclave together with 1.7 mmoles (1.175 g) of a rhodium catalyst with the formula Rh(CO)Cl(PPh₃)₂ and 19 mmoles (5 g) of triphenyl phosphine and reacted with a 1:1 mixture of hydrogen and carbon monoxide with intensive stirring for 5 hours at 100° C. under a pressure of 60 kg/cm² and in the absence of solvent. For working up, the contents of the reactor were filtered and distilled through a 20 cm Vigreux column.

Subsequent fractionation was carried out in a spinning band column. 29 g of a mixture of 2,6-dimethyl-1,5-diformylcyclooctane and 2,5-dimethyl-1,4diformylcyclooctane were obtained (boiling point: 105° C./16 mbar).

Odor description: green, potato note. 

What is claimed is:
 1. A method of providing a fragrance to a composition, said method comprising: (a) providing a composition; and (b) adding a fragrance-providing effective amount of a monocyclic aldehyde to the composition, wherein the monocyclic aldehyde is prepared by hydroformylation of a (di)methyl-substituted cyclooct(adi)ene.
 2. The method according to claim 1, wherein the monocyclic aldehyde comprises one or more compounds selected from the group consisting of general formulae 3a, 3b and 3c:


3. The method according to claim 1, wherein the monocyclic aldehyde is added in an amount of from about 0.001 to about 70% by weight, based on the combined weight of the composition and the monocyclic aldehyde.
 4. The method according to claim 2, wherein the monocyclic aldehyde is added in an amount of from about 0.001 to about 70% by weight, based on the combined weight of the composition and the monocyclic aldehyde.
 5. The method according to claim 1, wherein the monocyclic aldehyde is prepared by hydroformylation of a (di)methyl-substituted cyclooct(adi)ene at a temperature of about 100° C. and at a pressure of about 60 kg/cm².
 6. The method according to claim 1, wherein the composition is selected from the group consisting of cosmetic preparations, detergents, cleaning compositions, fabric softeners, textile treatment compositions, alcohol-based perfumes and tobacco.
 7. The method according to claim 2, wherein the composition is selected from the groups consisting of cosmetic preparations, detergents, cleaning compositions, fabric softeners, textile treatment compositions, alcohol-based perfumes and tobacco.
 8. A method of enhancing fragrance characteristics of a composition, said method comprising: (a) providing a composition comprising one or more fragrant components; (b) providing a monocyclic aldehyde to the composition, wherein the monocyclic aldehyde is prepared by hydroformylation of a (di)methyl-substituted cyclooct(adi)ene; and (c) combining the composition and a fragrance-enhancing effective amount of the monocyclic aldehyde.
 9. The method according to claim 8, wherein the monocyclic aldehyde comprises one or more compounds selected from the group consisting of general formulae 3a, 3b and 3c:


10. The method according to claim 8, wherein the monocyclic aldehyde is added in an amount of from about 0.001 to about 70% by weight, based on the combined weight of the composition and the monocyclic aldehyde.
 11. The method according to claim 9, wherein the monocyclic aldehyde is added in an amount of from about 0.001 to about 70% by weight, based on the combined weight of the composition and the monocyclic aldehyde.
 12. The method according to claim 8, wherein the monocyclic aldehyde is prepared by hydroformylation of a (di)methyl-substituted cyclooct(adi)ene at a temperature of about 100° C. and at a pressure of about 60 kg/cm².
 13. The method according to claim 8, wherein the composition is selected from the group consisting of cosmetic preparations, detergents, cleaning compositions, fabric softeners, textile treatment compositions, alcohol-based perfumes and tobacco.
 14. The method according to claim 9, wherein the composition is selected from the groups consisting of cosmetic preparations, detergents, cleaning compositions, fabric softeners, textile treatment compositions, alcohol-based perfumes and tobacco. 